An investment in quality of life
Do you know the best strategy to protect yourself from noise-induced hearing loss? Stay away from noisy environments! But sometimes this is simply not possible, for example, at the workplace. So you should make sure that you protect your hearing. Because one thing is certain: It may feel less comfortable wearing hearing protection, but this is nothing compared to noise-induced hearing loss that stays with you for life. If you want a good quality of life, it’s essential that your hearing is as undamaged as possible. This allows us to have carefree conversations, enjoy listening to music and hear all the important and beautiful little sounds in day-to-day life, from the door bell to the purr of the cat.
Make a conscious effort to protect your hearing in noisy situations because anyone who wants to rely on their hearing for life must make a conscious effort to protect it. This applies to both self-induced noise (e.g. listening to loud music with headphones, mowing the lawn, or going to rock concerts etc.) and unavoidable ambient noise, especially in the workplace. Because one thing is for definite: Continual strain on our hearing from exposure to high sound levels leads to hearing loss sooner or later.
A highly sensitive organ from an extremely quiet era
The environment of modern man comes with permanent, intense background noise: road traffic, babbling voices, constant background music. It’s never really quiet – and for many people not even at night. Yet our hearing is not created for this kind of stress. It evolved for life outdoors. Its tremendous sensitivity enabled our ancestors to survive by helping them hunt and reliably warn them of approaching dangers at any time. Additionally, there was communication with other people to consider. But in between there was often more or less silence; hearing was able to recover. Things are very different today: The noise levels of our immediate surroundings irritate our ears constantly, to a significant extent.
When is hearing irretrievably damaged?
Sound waves are converted into nerve impulses with the help of sensory cells in the cochlea of our inner ear. If these fine hairs are set in motion by sound waves, they convert the movement into electrical impulses. Each sensory cell is linked to a nerve fiber which is connected to the auditory center of the brain. The thick bundle of all these nerve fibers is known as the auditory nerve.
If you picture the hair cells as a kind of cornfield, then normal noises are comparable with slight gusts of wind blowing over the field and making the ears of corn gently wave back and forth. The louder the sounds, the stronger the wind and the more the ears become bent.
If extremely strong sound waves enter our ears, it’s like a storm sweeping over the cornfield. First, this stress wears out the sensory cells in the lower cochlear spiral of the inner ear. From then on, all sounds suddenly seem dull. The good news is that in this phase, the sensory cells are not yet permanently damaged and can fully recover if you take a long enough break from noise (over 14 hours): the hairs straighten up again.
However, if a sufficient break is not maintained, the sensory cells suffer permanent damage or even die from metabolic depletion: The hairs bend and remain horizontal. The problem with this is that dead sensory cells cannot be regenerated. So once noise-induced hearing loss has developed, it cannot be cured. And that’s not all. Noise-induced hearing loss often goes hand in hand with tinnitus.
Noise at work: Do I need hearing protection?
The daily noise exposure level is the time-weighted (average) noise exposure level over an 8-hour working day. It includes all sound events occurring at the workplace and must not exceed a specific maximum value. In the model Work Health and Safety Regulations the exposure standard for noise involves two measures:
- Over an eight-hour shift a worker can’t be exposed to more than 85 decibels.
- A worker can’t be exposed to a noise level above 140 decibels.
Specifically, this means that persons exposed to sound levels of 85 dB or more during work must wear ear protection. Incidentally, the pain threshold, i.e. the sound pressure level at which noise is painful, is 125 dB for most people. However, even a sustained noise level of 75 dB (equivalent to, for instance, a passing motorbike or train) can strain our hearing, although we don’t usually find this volume unpleasant.
What does the physical quantity dB actually stand for?
dB is the abbreviation for decibel. It is not a physical quantity such as meters or grams, but instead allows such quantities, in particular sound pressure, to be scaled. When expressed in dB, a 20 dB increase represents a tenfold increase in sound pressure. When handling data in decibels, it’s especially important to remember that an increase in the sound level by 10 dB feels twice as loud to our hearing.
Strategies for protecting our hearing
Turn it down!
Whether you’re listening to the radio, watching the TV or playing music with headphones or speakers: Make sure you don’t go over a reasonable volume. If in doubt, it’s better to turn it down.
Reduce sources of noise!
Simultaneous noises add up. So cut down on parallel noise sources, e.g. different music playing at the same time, loud conversations and running electrical appliances. It’s a strain for our ears to hear this all at once.
It's better to use quiet appliances!
This applies to drills, grinders and washing machines – but also dishwashers and fridges: Look out for the decibel rating when purchasing electrical appliances. The lower the rating, the quieter the appliance so the better it is for your ears.
Keep away from the source!
Always stay as far away as possible from the noise source – for example, a loud machine or speakers in a bar. If it gets too loud for you, get even further away, even if you have to leave the room.
Wear hearing protection!
Be consistent: whenever you're doing loud work such as mowing the lawn, sawing or drilling, always use earplugs or other suitable hearing protection.
Shut your ears!
This healthy reflex in children should also considered by adults: Put your fingers in your ears if you are exposed to acute noise levels, or press your palms firmly against your ears – and move away from the noise source!
Would you like to know how your hearing is?
How does hearing protection work?
Whether its earplugs, ear muffs, or capsule ear protection (which looks like headphones), hearing protection always has one purpose: to reduce harmful sound levels to a safe level. The employer is responsible for adopting appropriate measures as part of standard occupational safety.
Hearing protection is essentially made of a material which is a poor noise conductor. If sound waves come into contact with this material, they can pass through it only with considerable energy loss. In this way, the volume is reduced considerably. In concrete terms, the insulation value of individual hearing protection ranges from 25 to 40 dB. The level of insulation is very much dependent on the frequency, material and anatomy. To achieve higher insulation values, an ear protection system can be combined with capsule ear protection. In extremely noisy environments (measuring over 125 dB, e.g. at airports), complete soundproof suits are sometimes even used. They prevent the body from transmitting noise to the ears through the skeleton.
But however they’re designed, hearing protection systems cannot be expected to give complete silence. This is also quite intentional in professional use, so that employees can still hear important background noises such as voices (speech comprehension) or warning signals.
For specific applications, there are also capsule ear protection models, which simultaneously provide effective protection from noise while enabling communication (e.g. headphones in a helicopter) by using a microphone and electronics. This category also includes electronic “noise-canceling” headphones, which almost completely cancel outside noise in the earphones by means of phase shifting. You can find out more on this fascinating topic in the “Noise-Canceling” section below.
The key hearing protection categories
Ear protection capsules or capsule ear protection (ear muffs with a frame)
This headphone-type hearing protector is available in various designs. Some can be worn directly on the head, while others are designed to be fitted to a protective helmet. They usually fold up and are quick to put on, which is why they’re also well suited for short-term use. Depending on the design, they’re also suitable for high noise levels.
Earplug variant 1: Foam earplugs
These are the classic earplugs that everyone knows. They’re generally yellow, are made of expanding foam and are rolled up with your fingers into narrow cylinders before use. Once inserted into the auditory canal, they expand again within around 30 seconds, and adapt to the shape of the canal. These cheap earplugs are often used only once.
Earplug variant 2: Plastic earplugs
Thanks to their little hand grips and carry cord, these earplugs can be used and taken out much more quickly than their foam equivalents. This makes them ideal for work with alternating loud and quiet phases. Plastic earplugs are also available as so-called frame earplugs.
Earplug variant 3: Ear molds
Individually made for each wearer, this modern form of hearing protection offers maximum wearing comfort. The other major advantage of them is that different sound filters can be selected depending on the needs of the wearer. Take the following examples:
- For pure music pleasure, this filter enables a full sound experience while protecting against damage. Ideal for party- and concert-goers as well as musicians and DJs.
- For complete driving enjoyment, this filter protects motorcyclists from harmful engine noise.
- For carefree fun in the water, this filter keeps the ear canals of swimmers and water sports enthusiasts dry, protecting against ear infections.
- For undisturbed relaxation, this version helps you sleep well and concentrate on reading or working, especially when traveling.
- For active free time fun, whether at home, in your favorite bar, or when traveling, this ear protection is designed for active leisure activities.
This is the cheapest variant for single use. To achieve sufficient insulation and to stop cotton fibers remaining in the ear canal, each cotton earplug is surrounded by a thin film.
Warning! Making these yourself is not advisable!
Even if it sounds like a good idea, home-made earplugs made of cotton wool, sealant, rubber or even cigarette filters or other materials cannot provide sufficient hearing protection! On the contrary, they pose an additional risk: first, because they give you a false sense of security, and second, because they’re unhygienic and can lead to damage in the ear canal.
What should you do if no suitable hearing protection is available?
The best solution if you’re exposed to sudden noise, or are quickly passing through a noisy area, is to close your ears with your fingers (ensuring they’re as clean as possible) in the old-fashioned way. This provides good temporary protection.
Noise-canceling: Active noise control
Headphones with noise-canceling technology have become increasingly popular in recent years. This is because they can eliminate background noise at the touch of a button. They do this with the help of an electronic-acoustic trick, known as active noise control (ANC).
Noise-canceling specifically works when the headphone registers the background noise with the aid of a microphone and eliminates it with artificially generated “counter-noise” in the earpiece. The generated sound is the exact opposite of the background noise in its phase (phase-shifted), so the sound waves cancel each other out. An artificial, almost ghostlike silence is therefore created with the help of electronics in the soundproofed earpieces of the noise-canceling headphones.
When can you make good use of noise-canceling technology?
This is a familiar problem to most commuters or travelers: Listening to music, even with good-quality headphones, is not really any fun when the background noise becomes simply too intrusive. This includes people talking, the rattling of public transport, street noise, engine noise (e.g. when you’re on a bus) or the constant din of aircraft turbines. This is where noise-canceling technology comes in.
That said, noise-canceling headphones are not only suitable for uninterrupted listening to music via Bluetooth. They can also help you concentrate on work or studying despite background noise (such as the neighbors’ lawnmower, construction work in immediate proximity, ambient noise in open-plan offices etc.). Some athletes even use noise-canceling headphones instead of normal Bluetooth headphones to concentrate with as little disturbance as possible before competitions. Incidentally, even when noise-canceling is enabled, Bluetooth technology lets you receive and make phone calls without affecting quality.
What should you look for when buying noise-canceling headphones?
Noise-canceling headphones are now offered by almost all well-known headphone manufacturers. They’re always wireless or Bluetooth headphones. To choose the most suitable headset, you first need to know how and why you wish to use the headphones. The two main criteria to consider are: The noise reduction function and sound quality. If your priority is effective noise-canceling as opposed to sound quality, with noise reduction being just a nice additional effect, other devices are recommended.
Clinical picture of noise-induced hearing loss
Anyone who is often exposed to loud noises at work or in their private life, for long periods of time without wearing protection, has a high risk of developing noise-induced hearing loss. This condition first affects a person’s perception of higher, then middle and finally lower tones. This results in an abnormally large difference between the listening distances for conversations in normal speech or when whispering. However, you cannot become fully deaf from noise exposure alone.